Here, they have found that giving mice a fasting-mimicking, ketogenic diet (FMKD), which is a low-protein, low-sugar, and high-fat diet, switches on genes regulating processes associated with the growth of new beta cells.

Mice were placed on the FMKD only four days a week and given their normal chow on the remaining three days. They were calorie-restricted, fed 50 per cent of their normal daily calorie intake on day 1 and 10 per cent of normal daily calorie intake on days 2 to 4.

Researchers also controlled the timing of eating by doing the complete opposite of a typical Western meal pattern and have the mice eat their meals within the first few hours of the day (8am-10am). Control mice ate during the dark hours.

This is based on research showing that not only light and dark cycles regulate our biological clock - it is also controlled by nutrients. And that the typical Western eating pattern can actually be one of the factors which predisposes us to obesity.

After doing a few FMKD cycles of this 4:3 way of eating every ten days, the mice started to show reduced insulin resistance, a marked improvement in insulin production, and more stable levels of blood sugar.

When researchers looked for changes at a cellular level, they saw that genes normally active in the developing pancreases of young mice had been reactivated in the adult mice, thereby regenerating their beta cells.

Some of the principles of FMKD were tested on human pancreatic cells of type 1 diabetes donors and yield similar results. In humans too, the diet results in increased insulin production and the replication of beta cells.

It is unclear whether all of those beneficial effects seen can be attributed to the ketogenic aspect of the FMKD, or the fact that it is in sync with circadian clocks - which we know play a role in regulating beta cell health.